Some wearables such as the Apple Watch (from Series 5 and onward) allow you to record an electrocardiogram (ECG or EKG). Cardiogram itself does not take ECGs, but is able to import ECGs from Apple Watches and any other wearables that create ECGs in Apple Health.
At this time, ECGs from other wearables cannot be imported into Cardiogram. If you are experiencing difficulties with taking ECGs using your wearable, please reach out to your manufacturer’s support team (e.g., Apple Support, Fitbit Support). We plan to support ECGs once those manufacturers make that data available to apps such as Cardiogram.